1. Field of the Invention
The present invention relates to image processing techniques to display high quality images on graphic display devices such as TV that emphasize depth feeling on two-dimensional videos.
2. Description of the Related Art
As a conventional depth feeling enhancement technique, there is a technique to visually enlarge the difference between an object and a surrounding background by clarifying strong portions and weak portions in contour components (refer to Patent Document 1, for example). FIG. 2 shows a configuration diagram of an image processor (solid expression circuit) 900 that realizes a conventional depth feeling correction technique recited in the Patent Document 1.
In the image processor 900 shown in FIG. 2, data (input data) input from the input terminal is sent to an averaging circuit 101 and an edge enhancement process unit 140. The averaging circuit 101 averages the input data, and outputs the averaged data to a selector 103 via a delay circuit 102.
The edge enhancement process unit 140 includes a delay circuit 104, a contour extraction unit 105, a contour correction processing unit 106, and an adder circuit 108.
First, the contour extraction unit 105 extracts contour portions (contour components) through a digital filter, and outputs the result to the contour correction processing unit 106 and a threshold value processing unit 107. The threshold value processing unit 107 sends signals to the selector 103 for deciding the selection by the selector 103 in accordance with threshold value setting signal from the threshold value setting signal input terminal 120. The original signal delayed at the delay circuit 104 (signal corresponding to the input data) and contour components whose gain is adjusted by the contour correction processing unit 106 are added by the adder circuit 108, so that the added signal is output to the selector 103.
The selector 103 selects one from among the two input signals, i.e., the averaged data output from the delay circuit 102 and the edge enhancement data output from the adder circuit 108 in accordance with the selection signal from the threshold value processing unit 107, and outputs the selected one to an output terminal 130.
In the image processor 900 described as above, adaptively selecting one of the edge enhancement signal and the averaged signal makes it possible to clarify the difference between a portion having shapely defined contours forming a near view and a weak portion forming a distant view in the image, thereby making the image looking three-dimensional.    Patent Document 1 Unexamined Patent Publication JP2004-159148A (ninth page, FIG. 1)
However, in the conventional image processor 900, when the threshold value is changed in accordance with the threshold value setting signal, degree of alternative selection between the averaged data and the edge enhancement data is changed. For example, in the image processor 900, if the threshold value is lowered, an area to be judged to be an image whose edges should be enhanced increases and sizes (ratio) of the area to be enhanced and the area to be averaged is changed. However, in the conventional techniques, changes according to the above-described alteration is not applied to each of processes of changing degree of depth feeling generated by the difference in the degree of edge enhancement between the enhanced data and the averaged data.
Accordingly, if the depth feeling enhancement is considered to be TV image quality adjustment function, it has a problem that the user can not adjust the degree of depth feeling based on his or her preference.
The present invention is provided to solve the conventional problem, and it is an object of the present invention to provide an image processor, an image processing method, a program, a storage medium and an integrated circuit that can adjust the degree of depth feeling by the operation according to a one-dimensional parameter.